554 lines
16 KiB
C
554 lines
16 KiB
C
//*****************************************************************************
|
|
//
|
|
// am_hal_adc.c
|
|
//! @file
|
|
//!
|
|
//! @brief Functions for interfacing with the Analog to Digital Converter.
|
|
//!
|
|
//! @addtogroup adc2 Analog-to-Digital Converter (ADC)
|
|
//! @ingroup apollo2hal
|
|
//! @{
|
|
//
|
|
//*****************************************************************************
|
|
|
|
//*****************************************************************************
|
|
//
|
|
// Copyright (c) 2017, Ambiq Micro
|
|
// All rights reserved.
|
|
//
|
|
// Redistribution and use in source and binary forms, with or without
|
|
// modification, are permitted provided that the following conditions are met:
|
|
//
|
|
// 1. Redistributions of source code must retain the above copyright notice,
|
|
// this list of conditions and the following disclaimer.
|
|
//
|
|
// 2. Redistributions in binary form must reproduce the above copyright
|
|
// notice, this list of conditions and the following disclaimer in the
|
|
// documentation and/or other materials provided with the distribution.
|
|
//
|
|
// 3. Neither the name of the copyright holder nor the names of its
|
|
// contributors may be used to endorse or promote products derived from this
|
|
// software without specific prior written permission.
|
|
//
|
|
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
|
|
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
// POSSIBILITY OF SUCH DAMAGE.
|
|
//
|
|
// This is part of revision 1.2.11 of the AmbiqSuite Development Package.
|
|
//
|
|
//*****************************************************************************
|
|
|
|
#include "am_mcu_apollo.h"
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Private SRAM view of temperature trims.
|
|
//!
|
|
//! This static SRAM union is private to the ADC HAL functions.
|
|
//
|
|
//*****************************************************************************
|
|
static union
|
|
{
|
|
//! These trim values are loaded as uint32_t values.
|
|
struct
|
|
{
|
|
//! Temperature of the package test head (in degrees Kelvin)
|
|
uint32_t ui32CalibrationTemperature;
|
|
|
|
//! Voltage corresponding to temperature measured on test head.
|
|
uint32_t ui32CalibrationVoltage;
|
|
|
|
//! ADC offset voltage measured on the package test head.
|
|
uint32_t ui32CalibrationOffset;
|
|
|
|
//! Flag if default (guess) or measured.
|
|
bool bMeasured;
|
|
} ui32;
|
|
//! These trim values are accessed as floats when used in temp calculations.
|
|
struct
|
|
{
|
|
//! Temperature of the package test head in degrees Kelvin
|
|
float fCalibrationTemperature;
|
|
|
|
//! Voltage corresponding to temperature measured on test head.
|
|
float fCalibrationVoltage;
|
|
|
|
//! ADC offset voltage measured on the package test head.
|
|
float fCalibrationOffset;
|
|
|
|
//! Flag if default (guess) or measured.
|
|
float fMeasuredFlag;
|
|
} flt;
|
|
} priv_temp_trims;
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Configure the ADC.
|
|
//!
|
|
//! @param psConfig - pointer to the configuration structure for the ADC.
|
|
//!
|
|
//! This function may be used to perform the initial setup of the ADC based on
|
|
//! setting found in a configuration structure.
|
|
//!
|
|
//! @return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
am_hal_adc_config(am_hal_adc_config_t *psConfig)
|
|
{
|
|
//
|
|
// Set general ADC configuration parameters.
|
|
//
|
|
AM_REG(ADC, CFG) = (psConfig->ui32Clock |
|
|
psConfig->ui32TriggerConfig |
|
|
psConfig->ui32Reference |
|
|
psConfig->ui32ClockMode |
|
|
psConfig->ui32PowerMode |
|
|
psConfig->ui32Repeat |
|
|
AM_REG_ADC_CFG_ADCEN(1));
|
|
|
|
//
|
|
// Grab the temperature trims.
|
|
//
|
|
priv_temp_trims.ui32.ui32CalibrationTemperature =
|
|
am_hal_flash_load_ui32(AM_HAL_ADC_CALIB_TEMP_ADDR);
|
|
priv_temp_trims.ui32.ui32CalibrationVoltage =
|
|
am_hal_flash_load_ui32(AM_HAL_ADC_CALIB_AMBIENT_ADDR);
|
|
priv_temp_trims.ui32.ui32CalibrationOffset =
|
|
am_hal_flash_load_ui32(AM_HAL_ADC_CALIB_ADC_OFFSET_ADDR);
|
|
|
|
if ( (priv_temp_trims.ui32.ui32CalibrationTemperature == 0xffffffff) ||
|
|
(priv_temp_trims.ui32.ui32CalibrationVoltage == 0xffffffff) ||
|
|
(priv_temp_trims.ui32.ui32CalibrationOffset == 0xffffffff) )
|
|
{
|
|
//
|
|
// Since the device has not been calibrated on the tester, we'll load
|
|
// default calibration values. These default values should result
|
|
// in worst-case temperature measurements of +-6 degress C.
|
|
//
|
|
priv_temp_trims.flt.fCalibrationTemperature = AM_HAL_ADC_CALIB_TEMP_DEFAULT;
|
|
priv_temp_trims.flt.fCalibrationVoltage = AM_HAL_ADC_CALIB_AMBIENT_DEFAULT;
|
|
priv_temp_trims.flt.fCalibrationOffset = AM_HAL_ADC_CALIB_ADC_OFFSET_DEFAULT;
|
|
priv_temp_trims.ui32.bMeasured = false;
|
|
}
|
|
else
|
|
{
|
|
priv_temp_trims.ui32.bMeasured = true;
|
|
}
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Get the temperature trim parameters after configuring the ADC.
|
|
//!
|
|
//! @param pfTemp - pointer to a location to store the calibration temperature.
|
|
//! @param pfVoltage - pointer to a location to store the calibration voltage.
|
|
//! @param pfOffsetV - pointer to a location to store the calibration offset.
|
|
//!
|
|
//! This function may be used to access the actual temperature sensor trim
|
|
//! values from the private structure.
|
|
//!
|
|
//! WARNING: only call this after the ADC has been configured with
|
|
//! am_hal_adc_config.
|
|
//!
|
|
//! @return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
am_hal_adc_temp_trims_get(float * pfTemp, float * pfVoltage, float * pfOffsetV)
|
|
{
|
|
//
|
|
// Return trim temperature as a float, if you can.
|
|
//
|
|
if ( pfTemp != NULL )
|
|
{
|
|
*pfTemp = priv_temp_trims.flt.fCalibrationTemperature;
|
|
}
|
|
|
|
//
|
|
// Return trim voltage as a float, if you can.
|
|
//
|
|
if ( pfVoltage != NULL )
|
|
{
|
|
*pfVoltage = priv_temp_trims.flt.fCalibrationVoltage;
|
|
}
|
|
|
|
//
|
|
// Return trim ADC offset voltage as a float, if you can.
|
|
//
|
|
if ( pfOffsetV != NULL )
|
|
{
|
|
*pfOffsetV = priv_temp_trims.flt.fCalibrationOffset;
|
|
}
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Set the ADC window parameters.
|
|
//!
|
|
//! @param ui32Upper - the upper limit for the ADC window.
|
|
//! @param ui32Upper - the lower limit for the ADC window.
|
|
//!
|
|
//! This function may be used to change the ADC window parameters. Please note
|
|
//! that the upper and lower limits are only 16-bits wide in the ADC hardware.
|
|
//! This function will ignore the upper 16 bits of these arguments.
|
|
//!
|
|
//! @return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
am_hal_adc_window_set(uint32_t ui32Upper, uint32_t ui32Lower)
|
|
{
|
|
//
|
|
// Set the window limits for the ADC.
|
|
//
|
|
AM_BFW(ADC, WULIM, ULIM, ui32Upper);
|
|
AM_BFW(ADC, WLLIM, LLIM, ui32Lower);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Configure a single ADC slot.
|
|
//!
|
|
//! @param ui32SlotNumber - the number of the ADC slot to be configured.
|
|
//! @param ui32SlotConfig - contains slot-specific options.
|
|
//!
|
|
//! This function may be used to configure the settings for an individual ADC
|
|
//! slot. The parameter \b ui32SlotConfig should be the logical 'OR' of a slot
|
|
//! average macro, a slot hold-time macro, a slot channel macro, and
|
|
//! optionally, the slot window enable macro.
|
|
//!
|
|
//! @return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
am_hal_adc_slot_config(uint32_t ui32SlotNumber, uint32_t ui32SlotConfig)
|
|
{
|
|
uint32_t ui32RegOffset;
|
|
|
|
//
|
|
// Make sure we're accessing a real slot.
|
|
//
|
|
am_hal_debug_assert_msg((ui32SlotNumber & 0xFFFFFFFF0) == 0,
|
|
"Trying to configure an ADC slot that doesn't exist.");
|
|
|
|
//
|
|
// Locate the correct register for this ADC slot.
|
|
//
|
|
ui32RegOffset = (AM_REG_ADCn(0) + AM_REG_ADC_SL0CFG_O + (4 * ui32SlotNumber));
|
|
|
|
//
|
|
// Write the register with the caller's configuration value.
|
|
//
|
|
AM_REGVAL(ui32RegOffset) = ui32SlotConfig;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Peek at the next fifo entry.
|
|
//!
|
|
//! This function reads the oldest value in the ADC sample fifo but doesn't
|
|
//! actually advance the fifo to the next entry. This function is useful when
|
|
//! you need information from the fifo but you don't want to also empty the
|
|
//! fifo. This could be helpful if you want to check the FIFO depth without
|
|
//! pulling any data out.
|
|
//!
|
|
//! The value returned by this function is the raw 32-bit value provided by the
|
|
//! ADC hardware. In order to interpret this value, you will need to use one of
|
|
//! the following macros.
|
|
//!
|
|
//! @return 32-bit FIFO entry.
|
|
//!
|
|
//
|
|
//*****************************************************************************
|
|
uint32_t
|
|
am_hal_adc_fifo_peek(void)
|
|
{
|
|
uint32_t ui32FIFOValue;
|
|
|
|
//
|
|
// Grab a value from the ADC FIFO.
|
|
//
|
|
ui32FIFOValue = AM_REG(ADC, FIFO);
|
|
|
|
//
|
|
// Return FIFO entry.
|
|
//
|
|
return ui32FIFOValue;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief
|
|
//!
|
|
//! This function reads the oldest value in the ADC fifo and then pops the
|
|
//! fifo. Use this function when you actually want to pull data out of the
|
|
//! fifo.
|
|
//!
|
|
//! @return 32-bit FIFO entry.
|
|
//!
|
|
//
|
|
//*****************************************************************************
|
|
uint32_t
|
|
am_hal_adc_fifo_pop(void)
|
|
{
|
|
uint32_t ui32FIFOValue;
|
|
|
|
//
|
|
// Grab a value from the ADC FIFO.
|
|
//
|
|
ui32FIFOValue = AM_REG(ADC, FIFO);
|
|
|
|
//
|
|
// Pop the FIFO.
|
|
//
|
|
AM_REG(ADC, FIFO) = 0;
|
|
|
|
//
|
|
// Return FIFO valid bits.
|
|
//
|
|
return ui32FIFOValue;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Issue Software Trigger to the ADC.
|
|
//!
|
|
//! This function issues the software trigger to the ADC.
|
|
//!
|
|
//! @return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
am_hal_adc_trigger(void)
|
|
{
|
|
//
|
|
// Write to the Software trigger register in the ADC.
|
|
//
|
|
AM_REG(ADC, SWT) = 0x37;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Enable the ADC.
|
|
//!
|
|
//! Use this function to enable the ADC.
|
|
//!
|
|
//! @return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
am_hal_adc_enable(void)
|
|
{
|
|
//
|
|
// Enable the ADC.
|
|
//
|
|
AM_BFW(ADC, CFG, ADCEN, 0x1);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Disable the ADC.
|
|
//!
|
|
//! Use this function to disable the ADC.
|
|
//!
|
|
//! @return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
am_hal_adc_disable(void)
|
|
{
|
|
//
|
|
// Disable the ADC.
|
|
//
|
|
AM_BFW(ADC, CFG, ADCEN, 0x0);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Enable selected ADC Interrupts.
|
|
//!
|
|
//! @param ui32Interrupt - Use the macro bit fields provided in am_hal_adc.h.
|
|
//!
|
|
//! Use this function to enable the ADC interrupts.
|
|
//!
|
|
//! @return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
am_hal_adc_int_enable(uint32_t ui32Interrupt)
|
|
{
|
|
//
|
|
// Enable the interrupts.
|
|
//
|
|
AM_REG(ADC, INTEN) |= ui32Interrupt;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Return enabled ADC Interrupts.
|
|
//!
|
|
//! Use this function to get all enabled ADC interrupts.
|
|
//!
|
|
//! @return enabled ADC Interrupts.
|
|
//
|
|
//*****************************************************************************
|
|
uint32_t
|
|
am_hal_adc_int_enable_get(void)
|
|
{
|
|
//
|
|
// Return enabled interrupts.
|
|
//
|
|
return AM_REG(ADC, INTEN);
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Disable selected ADC Interrupts.
|
|
//!
|
|
//! @param ui32Interrupt - Use the macro bit fields provided in am_hal_adc.h.
|
|
//!
|
|
//! Use this function to disable the ADC interrupts.
|
|
//!
|
|
//! @return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
am_hal_adc_int_disable(uint32_t ui32Interrupt)
|
|
{
|
|
//
|
|
// Disable the interrupts.
|
|
//
|
|
AM_REG(ADC, INTEN) &= ~ui32Interrupt;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Clear selected ADC Interrupts.
|
|
//!
|
|
//! @param ui32Interrupt - Use the macro bit fields provided in am_hal_adc.h.
|
|
//!
|
|
//! Use this function to clear the ADC interrupts.
|
|
//!
|
|
//! @return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
am_hal_adc_int_clear(uint32_t ui32Interrupt)
|
|
{
|
|
//
|
|
// Clear the interrupts.
|
|
//
|
|
AM_REG(ADC, INTCLR) = ui32Interrupt;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Set selected ADC Interrupts.
|
|
//!
|
|
//! @param ui32Interrupt - Use the macro bit fields provided in am_hal_adc.h.
|
|
//!
|
|
//! Use this function to set the ADC interrupts.
|
|
//!
|
|
//! @return None.
|
|
//
|
|
//*****************************************************************************
|
|
void
|
|
am_hal_adc_int_set(uint32_t ui32Interrupt)
|
|
{
|
|
//
|
|
// Set the interrupts.
|
|
//
|
|
AM_REG(ADC, INTSET) = ui32Interrupt;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Return either enabled or raw selected ADC interrupt status.
|
|
//!
|
|
//! @param bEnabledOnly - return the status of only the enabled interrupts.
|
|
//!
|
|
//! Use this function to get the ADC interrupt status.
|
|
//!
|
|
//! @return enabled or raw ADC interrupt status.
|
|
//
|
|
//*****************************************************************************
|
|
uint32_t
|
|
am_hal_adc_int_status_get(bool bEnabledOnly)
|
|
{
|
|
//
|
|
// Return the status.
|
|
//
|
|
if (bEnabledOnly)
|
|
{
|
|
uint32_t u32RetVal = AM_REG(ADC, INTEN);
|
|
u32RetVal &= AM_REG(ADC, INTSTAT);
|
|
return u32RetVal;
|
|
}
|
|
else
|
|
{
|
|
return AM_REG(ADC, INTSTAT);
|
|
}
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
//! @brief Return temperature in degrees C of supplied voltage.
|
|
//!
|
|
//! @param fVoltage - return the temperature corresponding to this voltage.
|
|
//!
|
|
//! Use this function to convert volts from the temperature sensor into degrees
|
|
//! C. Caller converts ADC binary code to volts based on reference used.
|
|
//! This routine looks up the trim parameters and returns corrected temperature.
|
|
//!
|
|
//! The computation is based on a line running through 0 degrees K.
|
|
//! We find the slope from the trimmed temperature calibration point.
|
|
//!
|
|
//!
|
|
//! @return the temperature in degrees C.
|
|
//
|
|
//*****************************************************************************
|
|
float
|
|
am_hal_adc_volts_to_celsius(float fVoltage)
|
|
{
|
|
float fTemp;
|
|
|
|
//
|
|
// Get calibration temperature from trimmed values & convert to degrees K.
|
|
//
|
|
float fCalibration_temp = priv_temp_trims.flt.fCalibrationTemperature;
|
|
|
|
//
|
|
// Get remaining trimmed values.
|
|
//
|
|
float fCalibration_voltage = priv_temp_trims.flt.fCalibrationVoltage;
|
|
float fCalibration_offset = priv_temp_trims.flt.fCalibrationOffset;
|
|
|
|
//
|
|
// Compute the temperature.
|
|
//
|
|
fTemp = fCalibration_temp;
|
|
fTemp /= (fCalibration_voltage - fCalibration_offset);
|
|
fTemp *= (fVoltage - fCalibration_offset);
|
|
|
|
//
|
|
// Give it back to the caller in Celsius.
|
|
//
|
|
return fTemp - 273.15f;
|
|
}
|
|
|
|
//*****************************************************************************
|
|
//
|
|
// End Doxygen group.
|
|
//! @}
|
|
//
|
|
//*****************************************************************************
|